電機維修:電源方面使電動機過熱(re)的4個(ge)因素
1.電源電壓過高
當電(dian)(dian)源電(dian)(dian)壓過(guo)(guo)高時,電(dian)(dian)機的反電(dian)(dian)勢、磁通(tong)和磁通(tong)密(mi)度(du)增(zeng)(zeng)大(da)由于鐵(tie)(tie)損(sun)(sun)與磁通(tong)密(mi)度(du)的平方成正比(bi),鐵(tie)(tie)損(sun)(sun)增(zeng)(zeng)大(da),鐵(tie)(tie)心(xin)過(guo)(guo)熱(re)。然而,磁通(tong)量的增(zeng)(zeng)加會導致勵磁電(dian)(dian)流分量的急劇增(zeng)(zeng)加、1號定子繞組(zu)銅損(sun)(sun)的增(zeng)(zeng)加和繞組(zu)過(guo)(guo)熱(re)。因(yin)此,當電(dian)(dian)源電(dian)(dian)壓超(chao)過(guo)(guo)電(dian)(dian)動機的額(e)定電(dian)(dian)壓時,電(dian)(dian)動機就會過(guo)(guo)熱(re)。
2.電(dian)(dian)源電(dian)(dian)壓(ya)過低
當電源電壓過低時(shi),若電機(ji)的電磁(ci)轉(zhuan)矩不變(bian),磁(ci)通量(liang)減(jian)小,轉(zhuan)子(zi)電流相應增大,定子(zi)電流中的負載(zai)功率分量(liang)相應增大,導致繞組銅(tong)損增大,導致定子(zi)和轉(zhuan)子(zi)繞組過熱。
電動機(ji)過熱
3.電源電壓不(bu)對稱
當一(yi)(yi)相(xiang)電源線(xian)斷(duan)開,一(yi)(yi)相(xiang)保險絲熔斷(duan),或一(yi)(yi)相(xiang)因刀閘起動設備燒角而未接(jie)通時,三(san)相(xiang)電動機將經過(guo)(guo)一(yi)(yi)相(xiang),使兩相(xiang)繞組運行過(guo)(guo)熱,通過(guo)(guo)大電流燒毀。
4.三(san)相電(dian)源不平衡
當三相電(dian)源(yuan)不平(ping)衡時,電(dian)動(dong)機(ji)的三相電(dian)流不平(ping)衡,繞組過熱。
由上可(ke)知,電(dian)機(ji)過熱(re)時(shi),應首先考慮供電(dian)。確認電(dian)源沒有問題后,考慮其他因素(su)。